class_docstr: Base Class from Normalizing flows
  
  Args:
      model_config (BaseNFConfig): The configuration setting the main parameters of the
          model.
code: def _load_model_config_from_folder(cls, dir_path):
      file_list = os.listdir(dir_path)
  
      if "model_config.json" not in file_list:
          raise FileNotFoundError(
              f"Missing model config file ('model_config.json') in"
              f"{dir_path}... Cannot perform model building."
          )
  
      path_to_model_config = os.path.join(dir_path, "model_config.json")
      model_config = AutoConfig.from_json_file(path_to_model_config)
  
      return model_config
  
imports: import os
  import sys
  from copy import deepcopy
  import numpy
  import torch
  import torch.nn
  from ....data.datasets import BaseDataset
  from ...auto_model import AutoConfig
  from ...base.base_config import EnvironmentConfig
  from ...base.base_utils import ModelOutput
  from .base_nf_config import BaseNFConfig
label_desc: Use image node_id 6 for calling the BaseNF obj's underlying member method code with example usage: obj._load_model_config_from_folder(cls, dir_path) and returns: model_config